This invention relates generally to integrated gasification combined-cycle (IGCC) power generation systems, and more specifically to methods and apparatus for reducing the viscosity of gasifier slag.
At least some known IGCC systems include a gasification system that is integrated with at least one power producing turbine system. For example, known gasifiers convert a mixture of fuel, air or oxygen, steam, and/or limestone into an output of partially combusted gas, sometimes referred to as “syngas”. The hot combustion gases are supplied to the combustor of a gas turbine engine, which powers a generator that supplies electrical power to a power grid. Exhaust from at least some known gas turbine engines is supplied to a heat recovery steam generator that generates steam for driving a steam turbine. Power generated by the steam turbine also drives an electrical generator that provides electrical power to the power grid.
Some know gasification fuels, for example, heavy residual oils contain ash, metal, and mineral impurities. When gasified, the ash, metal, and mineral can form a high viscosity sludge that accumulates in the gasifier. The accumulation, over time leads to plugging which requires an undesirable change in gasifier operation such as at increased unconverted carbon or a switch to a more expensive higher quality feed.